A consideration of the U.S. and Russia in terms of power resources, which demonstrates a rivalry in the number of nuclear weapons but vast disparities between them in economics and state effectiveness, suggests that realist theory __________

a. overlooks the importance of economic power, as well as state effectiveness
b. is a strong predictor of interstate tension here, since only nuclear power matters, from the standpoint of realist theory
c. is inferior to liberal theory in its explanatory power, in regards to the renewed U.S.-Russian rivalry
d. cannot explain the renewed U.S.-Russian rivalry, since hard power realities do not seem to be driving it

Answer: D